Sulphur Free Composition And Lubricant Composition And Methods Thereof

ABSTRACT

A composition comprises a sulphur free reaction product of: (a)(i) a hydrocarbyl substituted aromatic compound containing an acidic group selected from the group consisting of a carboxylic group, a hydroxyl group and mixtures thereof; and (a)(ii) an organic nitrogen-containing base reacted with the acidic group. The composition is obtained by a preparatory process and is useful in a method for lubricating an internal combustion engine to include where the lubricant has reduced levels of sulphur, phosphorus and sulphated ash.

This application claims the benefit of U.S. Provisional Application No.60/441,516 filed on 21 Jan. 2003.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention involves a sulphur free composition, a compositioncontaining the sulphur free composition and an oil of lubricatingviscosity, and methods to prepare and use the sulphur free composition.The sulphur free composition is especially useful in lubricants for aninternal combustion engine by providing multifunctional performancewithout introducing sulphur and introducing at most only minor amountsof metal into the lubricant.

2. Description of the Related Art

Detergents are lubricant additive compositions that typically providedetergency performance to a lubricant composition that can includeneutralizing acids, preventing corrosion, and providing cleanliness bysuspending deposit forming substances and removing deposits. Detergentsgenerally consist of an anionic organic surfactant portion that usuallycontains sulphur such as an alkylarylsulphonate, a cationic metalcounterion, and a basic metal salt in a colloidal suspension thatprovides a base reserve for neutralizing acids. Various lubricantcompositions such as certain two-stroke engine oils and stationarynatural gas engine oils require detergency performance, but also requirethat the engine oil contain little or no metals for satisfactoryperformance. Dispersants provide cleanliness to all types of lubricantcompositions by suspending deposit forming substances.

It is also well known for lubricating oils to contain a number ofadditives used to protect the engine from wear, the accumulation ofdeposits, and filter plugging. Common additives for engine lubricatingoils include zinc dialkyldithiophosphates (ZDDP) as antiwear additivesand alkali and alkaline earth metal overbased sulphonate and phenatedetergents. It is believed that ZDDP antiwear additives protect theengine by forming a protective film on metal surfaces. Typical treatmentquantities of ZDDP range from 1 to 2 weight percent based on the totalweight of the lubricant. Detergents such as overbased calciumsulphonates help keep the engine parts clean of deposits and offer analkalinity reserve. Typical treatment quantities of detergents rangefrom 0.05 to 10 weight percent based on the total weight of thelubricant.

Current and future regulations regarding exhaust emissions from internalcombustion engines that contain exhaust treatment devices are requiringa reduction in the sulphur, phosphorus and metal content of engine oilsused in these engines. This reduction in the sulphur, phosphorus andmetal content of engine oils is being implemented because it is thoughtthat they can adversely affect the performance of exhaust treatmentdevices.

Any reduction in the performance of catalytic converters tends to resultin increased amounts of greenhouse gases such as nitric oxide and/orsulphur oxides. However, reducing the amount of ZDDP will increase theamount of wear in an engine. Also reducing the amount of detergent willdecrease engine cleanliness and result in increased deposits.

International Publication No. WO 03/18728 (Moreton et al.) discloses alinear compound containing phenolic and salicylic units and a metal saltor boron-containing metal salt thereof and use of the compound and thesalts in a lubricating oil composition.

International Publication No. WO 01/56968 (Taylor et al.) discloses acyclic compound for use in a fuel and a lubricating oil compositionwhere the cyclic compound comprises carboxyl-substituted and/orhydroxyl-substituted aromatic units joined together to form a ring andthe carboxyl substituent can be present as an acid or as a carboxylicsalt with a metal or ammonium cation.

U.S. Pat. No. 5,688,751 (Cleveland et al.) discloses a mixture of an oilof lubricating viscosity and a hydrocarbyl-substituted hydroxyaromaticcarboxylic acid or an ester, amide, ammonium or amine salt, ormonovalent metal salt thereof for lubrication of two-stroke cycleengines.

U.S. Pat. No. 6,310,009 (Kocsis et al.) discloses a saligenin derivativeand a lubricating oil composition comprising the saligenin derivative.

U.S. Pat. No. 5,202,038 (Schoch et al.) discloses salts which can beused as antiwear additives for lubricants and which are formed by afatty amine with a mixture of a monocarboxylic acid and a dicarboxylicacid where the acids contain a perfluoroalkyl radical.

It has now been found that the composition of the present inventionprovides detergency, antiwear and dispersancy performance to acomposition such as an engine oil and is free of sulphur and metals orcontains only a minor amount of metals.

SUMMARY OF THE INVENTION

The present invention provides a composition comprising:

(a) a sulphur free reaction product of:

-   -   (i) a hydrocarbyl substituted aromatic compound containing an        acidic group selected from the group consisting of a carboxylic        group, a hydroxyl group and mixtures thereof; and    -   (ii) an organic nitrogen-containing base reacted with the acidic        group; and

(b) an oil of lubricating viscosity.

The invention further provides a composition comprising:

(a) a sulphur free reaction product of:

-   -   (i) a hydrocarbyl substituted aromatic compound containing a        carboxyl and/or hydroxyl acidic group and selected from the        group consisting of (1) an oligomeric reaction product of a        hydrocarbyl-substituted phenol, an aldehyde, and a        carboxyl-substituted phenol; (2) an oligomeric reaction product        of a hydrocarbyl-substituted phenol, an aldehyde, and a        carboxyl-substituted phenylamine; and mixtures thereof; and    -   (ii) an organic nitrogen-containing base reacted with the acidic        group of (a)(i).

The invention further provides a process for the preparation of acomposition comprising:

(a) heating reactants (a)(i) and (a)(ii) as described above andhereinbelow;

(b) optionally holding the product of step (a) under vacuum; and

(c) adding the product of step (a) or (b) to an oil of lubricatingviscosity.

The invention also provides a use of the inventive composition forimparting to an internal combustion engine an improvement in one or moreperformance properties selected from the group selected consisting ofcleanliness, wear and exhaust emissions.

The invention additionally provides a method of lubricating and ofimproving the performance of an internal combustion engine comprisingsupplying to the engine a lubricant composition comprising the sulphurfree reaction product of components (a)(i) and (a)(ii) as describedthroughout this application.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a composition comprising:

(a) a sulphur free reaction product of:

-   -   (i) a hydrocarbyl substituted aromatic compound containing an        acidic group selected from the group consisting of a hydroxyl        group, a carboxylic group and mixtures thereof; and    -   (ii) an organic nitrogen-containing base reacted with the acidic        group; and

(b) an oil of lubricating viscosity.

Throughout this application the term hydrocarbyl represents a univalentgroup of one or more carbon atoms that is predominately hydrocarbon innature, but can contain heteroatoms such as oxygen in the carbon chainand can have nonhydro-carbon and heteroatom-containing groups such ashydroxy, halo, nitro and alkoxy attached to the carbon chain.

Component (a) of the composition of this invention in addition to beingfree of sulphur can be free of a metal by having no sulphated ash, asdetermined by American Society for Testing and Materials specificationASTM D-874, or can contain a minor amount of metal by having a sulphatedash on a weight basis below 0.5%, below 0.25% or below 0.1%.

Often the composition has a total base number (TBN). Often the TBN ofthe composition is 3 or higher, in one aspect 5 or higher, and in yetanother aspect 9 or higher.

Component (a) of the composition is often present on a weight basis at0.01 to 40%, in another aspect at 0.5 to 40%, in yet another aspect at0.75 to 20% and yet another aspect at 1 to 15% of the composition.

Often (a)(i) is at least one member selected from the group consistingof (1) an oligomeric reaction product of an hydrocarbyl-substitutedphenol, an aldehyde, and a carboxyl-substituted phenol; (2) anoligomeric reaction product of a hydrocarbyl-substituted phenol, analdehyde, and a carboxyl-substituted phenylamine; (3) ahydrocarbyl-substituted, carboxyl-substituted phenol; (4) ahydrocarbyl-substituted, carboxyl-substituted phenylamine; and (5) anoligomeric reaction product of an hydrocarbyl-substituted phenol and analdehyde. In one embodiment of the invention (a)(i) is an oligomericspecies, and in other embodiments (a)(i) is (a)(i)(1), (a)(i)(2), or amixture thereof. In another embodiment of the invention the carboxylicor carboxyl group substituted on a phenol or phenylamine of thisinvention is an acid group —CO₂H, and in other embodiments is an estergroup —CO₂R where R is a hydrocarbyl group or is a mixture of acid andester groups.

Often (a)(ii) is at least one member selected from the group consistingof (1) an amino-containing imine or a reactive equivalent thereof; (2)ammonia or a reactive equivalent thereof; (3) a monoamine; (4) apolyamine; (5) a nitrogen containing heterocycle; (6) an aminoalcohol;(7) a tetraalkylammonium salt; and (8) a non-heterocyclic aromaticamine.

The invention further provides a composition comprising:

(a) a sulphur free reaction product of:

-   -   (i) a hydrocarbyl substituted aromatic compound containing a        carboxyl and/or hydroxyl acidic group and selected from the        group consisting of (1) an oligomeric reaction product of an        hydrocarbyl-substituted phenol, an aldehyde, and a        carboxyl-substituted phenol; (2) an oligomeric reaction product        of a hydrocarbyl-substituted phenol, an aldehyde, and a        carboxyl-substituted phenylamine; and mixtures thereof; and    -   (ii) an organic nitrogen-containing base reacted with the acidic        group of (a)(i).

Hydrocarbyl Substituted Aromatic Compound

The hydrocarbyl substituent of the hydrocarbyl-substituted phenol of thereactant (a)(i)(1) or (a)(i)(2) may have 1 to 60 carbon atoms, inanother aspect 4 to 50 carbon atoms, and in a further aspects 6 to 40 or7 to 30 carbon atoms. The hydrocarbyl substituent is often alkyl and inanother aspect is derived from an olefin. The alkyl substituent is oftenderived from a polyolefin which may be a homopolymer from one olefinmonomer or a copolymer from a mixture of two or more olefin monomers.The olefin monomer may be an alpha-olefin, an internal olefin, or apolyene and includes ethylene, propylene, butene isomers, penteneisomers, decene isomers, and dienes. Useful polyolefins arepolypropylenes and polyisobutylenes. Methods to prepare the polyolefinsand the alkylphenols via alkylation of phenol with olefins orpolyolefins are well known.

The aldehyde of the reactant of (a)(i)(1) or (a)(i)(2) may have 1 to 6carbon atoms. The aldehyde may be formaldehyde in one of its reactiveforms such as formalin or paraformaldehyde. The carboxyl-substitutedphenol of the reactant of (a)(i)(1) may be a 2- or 3- or4-hydroxybenzoic acid or a dihydroxybenzoic acid such as3,5-dihydroxybenzoic acid. The carboxyl substituted phenol may havealkyl substituents. A useful carboxyl-substituted phenol is salicylicacid. The carboxyl substituted phenylamine of the reactant (a)(i)(2) isnormally anthranilic acid and can contain additional alkyl, hydroxyl oramino substituents. The oligomeric reaction product of (a)(i)(1) or(a)(i)(2) contains at least one hydrocarbyl-substituted phenol unit andat least one carboxyl-substituted phenol or carboxyl-substitutedphenylamine unit. The oligomeric reaction product of (a)(i)(1) or(a)(i)(2) may contain 2 to 20 phenol or phenylamine units, 2 to 10phenol or phenylamine units, or 2 to 8 phenol or phenylamine units. Theoligomeric reaction product of (a)(i)(1) or (a)(i)(2) may include linearmolecules, cyclic molecules, or mixtures thereof. In an embodiment ofthe invention the oligomeric reaction product of (a)(i)(1) or (a)(i)(2)is a mixture of linear and cyclic molecules, and in another embodimentthe mixture contains a majority of linear molecules.

The oligomeric reaction products of (a)(i)(1) and (a)(i)(2) may beprepared as described in U.S. Pat. No. 6,200,936 and/or in PreparativeExamples A-E hereinbelow using a basic catalyst and a solvent. Basiccatalysts include alkali and alkaline earth metal bases and amines suchas lithium hydroxide, sodium hydroxide, potassium hydroxide and ammoniumhydroxide. A solvent may be employed in the preparation of theoligomeric reaction product of (a)(i)(1) or (a)(i)(2) up to 90% byweight of the reaction mixture. The mole ratio of thehydrocarbyl-substituted phenol to the carboxyl-substituted phenol orphenylamine is often in the range from 1:0.05 to 1:19, and in a furtherembodiment of the invention is about 2 hydrocarbyl-substituted phenolsto 1 carboxyl-substituted phenol or phenylamine. The mole ratio ofcombined hydrocarbyl-substituted phenol and carboxyl-substituted phenolor phenylamine to aldehyde may be 1:0.5-3.

The oligomeric reaction products of (a)(i)(1) and (a)(i)(2) can be asubstantially linear compound comprising at least one unit of theformulae (I) or (II), provided U is —OH for (a)(i)(1) and U is selectedfrom the group consisting of —NH₂—NHR¹, —N(R¹)₂ and mixtures thereof for(a)(i)(2):

each end of the compound having a terminal group of formulae (III) or(IV):

such groups being linked by divalent bridging groups, which may be thesame or different for each linkage; wherein f is 1, 2 or 3, in oneaspect 1 or 2; R¹ is a hydrocarbyl group containing 1 to 5 carbon atoms;R² is hydroxyl or a hydrocarbyl group and j is 0, 1, or 2; R³ ishydrogen or a hydrocarbyl group; R⁴ is a hydrocarbyl group or asubstituted hydrocarbyl group; g is 1, 2 or 3, provided at least one R⁴group contains 8 or more carbon atoms; and wherein the compound onaverage contains at least one of unit (I) or (III) and at least one ofunit (II) or (IV) and the ratio of the total number of units (I) and(III) to the total number of units of (II) and (IV) in the compositionis about 0.1:1 to about 2:1.

The U group in formulae (I) and (III) may be located in one or morepositions ortho, meta, or para to the —COOR³ group. In one aspect the Ugroup is located ortho to the —COOR³ group. When the U group is a —OHgroup, formulae (I) and (III) are derived from 2-hydroxybenzoic acid(often called salicylic acid), 3-hydroxybenzoic acid, 4-hydroxybenzoicacid or mixtures thereof. When U is a —NH₂ group, formulae (I) and (III)are derived from 2-aminobenzoic acid (often called anthranilic acid),3-aminobenzoic acid, 4-aminobenzoic acid or mixtures thereof.

The divalent bridging group, which may be the same or different in eachoccurrence, includes a methylene bridge such as —CH₂— or —CH(R)— and anether bridge such as —CH₂OCH₂— or —CH(R)OCH(R)— where R is an alkylgroup having 1 to 5 carbon atoms and where the methylene and etherbridges are derived from formaldehyde or an aldehyde having 2 to 6carbon atoms.

Often the terminal group of formulae (III) or (IV) contains 1 or 2hydroxymethyl groups ortho to a hydroxy group. Often the hydroxymethylgroups are present from 0 to 30 wt % of (a)(i)(1) and/or (a)(i)(2), inone aspect 0.1 to 20 wt % of (a)(i)(1) and/or (a)(i)(2), in anotheraspect 0.2 to 10 wt % of (a)(i)(1) and/or (a)(i)(2) and in yet anotheraspect 0.3 to 5 wt % of (a)(i)(1) and/or (a)(i)(2). In one embodiment ofthe invention hydroxymethyl groups are present. In one embodiment of theinvention hydroxymethyl groups are not present.

In an embodiment of the invention the sulphur free reaction product ofcomponent (a) as described throughout this application can be a reactionproduct of components (a)(i), (a)(ii) and (a)(iii) a metal-containingbase. The metal-containing base can be any reactive inorganic metalcompound or mixture of compounds to include alkali and alkaline earthmetal compounds such as oxides, hydroxides and carbonates like calciumhydroxide. The ratio of equivalents of (a)(i) to moles of (a)(ii) toequivalents of (a)(iii) can be respectively 1:0.25-2:0.25-2, and inother instances can be 1:0.25-1.5:0.5-2 or 1:0.4-1:1-1.7. In a furtherembodiment of the invention the reaction product of (a)(i), (a)(ii) and(a)(iii) is combined with an oil of lubricating viscosity or with an oilof lubricating viscosity and at least one other performance additive asdescribed hereinbelow. The reaction product of (a)(i), (a)(ii) and(a)(iii) can be prepared as described in Example 14 below.

It is believed prior to neutralization that a significant fraction ofthe molecules of the oligomeric reaction product of component (a)(i)(1),as described above, can be represented on average by the followingformula (V):

wherein each R⁵ may be the same or different and is hydrogen or an alkylgroup provided at least one R⁵ is alkyl. In an embodiment R⁵ is derivedfrom a polyisobutylene having a number average molecular weight of 200to 5000, and in other instances of 300 to 1000 and 400 to 700.Significant amounts of di- or trinuclear species may also be presentcontaining one or two salicylic end groups of formula (III). Theneutralized oligomeric reaction product of component (a)(i)(1) may beused alone or with other detergents.

The hydrocarbyl substituent of the hydrocarbyl-substituted,carboxyl-substituted phenol of the component (a)(i)(3) is often alkyland in one aspect derived from an olefin or a polyolefin. The polyolefinmay be prepared from ethylene, propylene, or a butylene such asisobutylene. The olefin or polyolefin often contains 4 to 50 carbonatoms, in another aspect 6 to 40 carbon atoms and in yet another aspect7 to 30 carbon atoms. The hydrocarbyl-substituted, carboxyl-substitutedphenol may be an alkyl-substituted salicylic acid which is generallyavailable commercially as a metal salt or may be prepared by well knownmethods such as via the Kolbe-Schmidt reaction of carbon dioxide with analkali metal phenolate salt.

The hydrocarbyl substituent of the hydrocarbyl-substitutedcarboxyl-substituted phenylamine of component (a)(i)(4) is generally analkyl group as described above for component (a)(i)(3). An example ofcomponent (a)(i)(4) is an alkyl-substituted anthranilic acid.

The hydrocarbyl substituent of the hydrocarbyl-substituted phenol of theoligomeric reaction product of (a)(i)(5) is generally an alkyl group asdescribed above for component (a)(i)(3) and includes alkyl groupsderived from polypropylenes such as an isopropylene tetramer. Theoligomeric reaction product of component (a)(i)(5) can be prepared byreacting an alkylphenol such as a dodecylphenol and an aldehyde such asformaldehyde in the presence of an acidic or basic catalyst or in thepresence of a stoichiometric amount of a metal containing base asdescribed in U.S. Pat. No. 3,256,183 where the product can be treatedwith an acid to give a metal free product. Since the oligomeric reactionproduct of component (a)(i)(5) may be weakly acidic, it is advantageousto use a strong organic nitrogen-containing base such as atetraalkylammonium hydroxide to neutralize component (a)(i)(5).

The organic nitrogen-containing base of the present invention may be(a)(ii)(1) an amino-containing imine, a reactive equivalent thereof, ormixtures thereof. The amino-containing imine may be at least oneselected from guanidine, aminoguanidine, 1,3-diaminoguanidine,formamidine, benzamidine, 3- or 4-aminobenzamidine, acetamidine, andreactive equivalents thereof. Reactive equivalents of this imine may besalts of the imine with acids to include hydrogen chloride, carbonicacid, and carboxylic acids such as formic acid and acetic acid. Examplesof reactive equivalents of the imines are guanidine carbonate,aminoguanidine bicarbonate, or acetamidine hydrogen chloride.

The organic nitrogen-containing base may be (a)(ii)(2) ammonia or areactive equivalent thereof which may be a salt of ammonia with acids toinclude water, hydrogen chloride, carbonic acid, and carboxylic acidssuch as formic and acetic acid.

The monoamine of (a)(ii)(3) often includes a hydrocarbyl-substitutedprimary, secondary or tertiary monoamine or mixture thereof. Often thehydrocarbyl group is an alkyl group. Each hydrocarbyl group oftencontains 1 to 40 carbon atoms, in another aspect 4 to 30 carbon atomsand in yet another aspect 6 to 20 carbon atoms. The hydrocarbyl groupmay be substituted or unsubstituted, branched or unbranched and in oneaspect the hydrocarbyl group is unsubstituted. Examples of a suitablemonoamine include methylamine, ethylamine, diethylamine, triethylamine,butylamine, dibutylamine, triethylamine, hexylamine, dihexylamine,trihexylamine, 2-ethylhexylamine, di(2-ethylhexyl)amine,tri(2-ethylhexyl)amine, nonylamine, dinonylamine, trinonylamine,dodecylamine, didodecylamine, pentadecylamine, dipentadecylamine,tripentadecylamine, octadecylamine, dioctadecylamine, trioctadecylamine, and Primene® 81R which is a mixture of C₁₁ to C₁₄ tertiary alkylprimary amines available from Rohm & Haas.

The polyamine of (a)(ii)(4) can contain two or more amino groups whereeach amino group can be a primary, secondary or tertiary amino group.The polyamine of (a)(ii)(4) can be an alkylenediamine, apolyalkylenepolyamine such as a polyethylenepolyamine, or a mixturethereof. Useful examples of polyamines are ethylenediamine,propylenediamine, 1,3-diaminopropane, N-methylethylenediamine,diethylenetriamine, triethylenetetramine, tris(2-aminoethyl)amine, andpolyethylenepolyamine bottoms.

The nitrogen containing heterocycle of (a)(ii)(5) can include aheterocycle having an aromatic and/or nonaromatic ring system thatincludes one or more nitrogen atoms. Often the ring system contains atleast 5 or 6 atoms, although the ring systems may contain up to 15, inone aspect up to 12 and in yet another aspect up to 10 atoms. The numberof nitrogen atoms in the ring system is often from 1 to 5, in one aspect1 to 4 and in yet another aspect 1 to 3. The ring system may besubstituted or unsubstituted, branched or unbranched. In one aspect thering system is unsubstituted. The nitrogen containing heterocycle caninclude for example a pyrrole, a pyrrolidine, an imidazole, animidazoline, a piperazine, a pyrazole, an oxazole, a pyridine, apiperidine, a pyrimidine, a purine, a benzotriazole, a 1,2,4-triazole, aquinoline, an isoquinoline, a carbazole or mixtures thereof. In oneembodiment the nitrogen containing heterocycle is selected from thegroup consisting of a pyrrole, an imidazole, an imidazoline, a pyrazoleand mixtures thereof.

The aminoalcohol of (a)(ii)(6) can contain one or more hydroxyl groupsand one or more amino groups. The aminoalcohol in embodiments of thisinvention can contain 1 to 6 or 1 to 3 hydroxyl groups, 1 to 8 or 1 to 2amino groups, and 2 to 50 or 2 to 40 or 2 to 25 or 2 to 15 carbon atoms.The aminoalcohol can be a monoalkanolamine, a dialkanolamine, atrialkanolamine or mixtures thereof. The aminoalcohol can include forexample ethanolamine, isopropanolamine, diethanolamine, triethanolamine,N,N-diethylethanolamine, N,N-dimethylethanolamine,N,N-dibutylethanolamine, 3-amino-1,2-propanediol, serinol,2-amino-2-methyl-1,3-propanediol, tris(hydroxymethyl)-aminomethane,diisopropanolamine, N-methyldiethanolamine, and2-(2-aminoethylamino)ethanol.

The organic nitrogen-containing base may be (a)(ii)(7) atetraalkylammonium salt. The tetraalkylammonium salt can have 4 or morecarbon atoms. The tetralkylammonium salt generally has a hydroxide anionor a reactive equivalent thereof to include a chloride, a carbonate, abicarbonate, or a carboxylic acid anion such as formate or acetate. Thetetraalkylammonium salt can be for example tetramethylammonium hydroxideor hexadecyltrimethylammonium hydroxide.

The non-heterocyclic aromatic amine of (a)(ii)(8) can contain one ormore amino groups attached to a hydrocarbon aromatic ring system wherethe amino groups and ring system can be substituted or not substituted.The non-heterocyclic aromatic amine can include aminophenols, alkylsubstituted aminophenols, phenylenediamines, and N-substitutedphenylenediamines. The amine of (a)(ii)(8) can include for exampleaniline, 1,4-phenylenediamine, N-phenyl-1,4-phenylenediamine,N,N-dimethyl-1,4-phenylenediamine, and 2-amino-p-cresol.

In an embodiment of the invention the sulphur free reaction product of(a)(i) and (a)(ii) is a reaction product of (a)(i)(1) or (a)(i)(2) or(a)(i)(3) or (a)(i)(4) or (a)(i)(5) or mixtures thereof and (a)(ii)(1).In another embodiment of this invention the sulphur free reactionproduct is formed from (a)(i)(1) or (a)(i)(2) and (a)(ii)(1). In afurther embodiment of the invention the sulphur free reaction product isformed from (a)(i)(1) and (a)(ii)(1). The sulphur free reaction productformed by reacting one or more members of component (a)(i) and anamino-containing imine of component (a)(ii)(1) is useful in the oilcontaining composition and methods of this invention.

Oils of Lubricating Viscosity

An oil of lubricating viscosity can be added to the sulphur freereaction product of (a)(i) and (a)(ii) of the present invention to forma composition which can be a lubricant composition such as an engine oilfor an internal combustion engine. The oil of lubricating viscosity canbe a natural oil, a synthetic oil, or a mixture thereof. Natural oilscan include animal oils, plant oils, mineral oils from petroleum or coalor shale sources, and mixtures thereof. Mineral oils can includeunrefined, refined and re-refined oils and mixtures thereof. Refined andre-refined mineral oils can include the American Petroleum Institute(API) Group I, II and III base oils. The oil of lubricating viscositycan include for example API Group III base oils such as Nexbase™ 3050,Nexbase™ 3043, Yubase™ 4, Yubase™ 6, Yurong™ 150N, Yurong™ 500N andShell™ XHVI 5.2. Synthetic oils can include olefin polymers such aspoly(alpha-olefin)s and hydrogenated poly(alpha-olefin)s, alkylatedaromatics such as dodecylbenzene, carboxylic acid esters, andhydrocarbons from a gas-to-liquid process such as the Fischer-Tropschprocess. The oil of lubricating viscosity can be present in thecomposition of the present invention on a weight basis at up to 99.99%,and in other embodiments at up to 99%, 95%, 90% or 80%.

Other Performance Additives

The composition of the present invention which contains the reactionproduct of (a)(i) and (a)(ii) can include other performance additives.The other performance additives can include metal deactivators such asbenzotriazole derivatives, detergents such as sulphonates and phenatesand carboxylates neutralized or overbased with metal bases, dispersantssuch as Mannich bases and succinimides generally prepared frompolyisobutylenes having a number average molecular weight of 300 to3000, antioxidants such as alkylated diphenylamines and hindered phenolsand hindered phenol derivatives and mixtures thereof, antiwear agents toinclude zinc dialkyl dithiophosphates, corrosion inhibitors,antiscuffing agents, extreme pressure agents, foam inhibitors includingsilicone oils, demulsifiers, friction modifiers including amide andester derivatives of fatty carboxylic acids, viscosity modifiers toinclude various polymeric viscosity index improvers and pour pointdepressants, seal swell agents, and mixtures thereof. Typically a fullyformulated lubricating oil will contain one or more of these additives.The composition of the present invention, which comprises a sulphur freereaction product of (a)(i) and (a)(ii) or the sulphur free reactionproduct and an oil of lubricating viscosity, can further comprise atleast one other performance additive as described above, and in anotherembodiment of the invention can comprise at least one other performanceadditive selected from the group consisting of dispersants antioxidants,foam inhibitors, demulsifiers, friction modifiers, and viscositymodifiers. The other performance additive or additives can be present ona weight basis in a composition of the present invention at 0 to 30%,and in other embodiments can be present at 0.0001 to 30%, at 0.001 to20%, or at 0.001 to 15%.

Process

The invention further provides a process for the preparation of acomposition comprising:

(a) heating reactants (a)(i) and (a)(ii) often to a temperature of 50°C. to 200° C., in one aspect at 60° C. to 175° C., and in another aspectat 70° C. to 150° C. to form a product;

(b) optionally holding the product of step (a) under vacuum; and

(c) adding the product of step (a) or (b) to an oil of lubricatingviscosity.

The reaction may be run using an oil of lubricating viscosity, water,alcohols, aliphatic and aromatic hydrocarbons such as toluene or xylene,or a mixture thereof to serve as a diluent and/or solvent. Solvents canbe added anytime during the reaction process of steps (a) and (b).Diluents such as an oil can be added anytime before, during or after thereaction process.

In step (a), reactants (a)(i) and (a)(ii) can be combined and then thecombination heated and stirred to form a product or a reactant can beheated and stirred and a second reactant added to the first reactantfollowed by heating and stirring to form a product. Often the reactiontime is 30 seconds to 48 hours, in one aspect 2 minutes to 24 hours, inanother aspect 5 minutes to 16 hours and in yet another aspect 10minutes to 8 hours often at pressures of 86 kPa to 266 kPa (645 mm Hg to2000 mm Hg), in one aspect 91 kPa to 200 kPa (690 mm Hg to 1500 mm Hg),and in another aspect 95 kPa to 133 kPa (715 mm Hg to 1000 mm Hg).

In step (b) the vacuum is often at pressures of 1 kPa to 85 kPa (7 mm Hgto 638 mm Hg), in one aspect 4 kPa to 70 kPa (30 mm Hg to 526 mm Hg) andin another aspect 6 kPa to 60 kPa (45 mm Hg to 450 mm Hg) for a periodof time sufficient to substantially remove solvent and reactionby-products such as water.

The process optionally includes mixing other performance additives asdescribed above at the end of step (a) and/or the end of step (b) or atany point during or after step (c).

An embodiment of the invention is a product prepared by the abovedescribed process of preparation comprising step (a) and optional steps(b) and (c).

When the composition of the present invention comprises the sulphur freereaction product and an oil of lubricating viscosity it can be termed anadditive composition. Generally when this additive composition iscombined with other performance additives the combination can be termeda concentrate composition although a concentrate composition can containa single additive. The additive composition or concentrate compositioncan be further diluted with an oil to form a lubricant composition, suchas an engine oil for an internal combustion engine, containing anadditive or additives at a level sufficient to provide satisfactoryperformance. The oil level in an additive or concentrate composition forfluidity and handleability purposes will generally be on a weight basis10 to 90%, and in other instances be 20 to 80%, or 30 to 70%.

INDUSTRIAL APPLICATION

The composition of the present invention is useful in an internalcombustion engine including a spark-ignited engine or acompression-ignited engine. Suitable examples of an engine include adiesel fuelled engine, a gasoline fuelled engine, a natural gas fuelledengine or a mixed gasoline/alcohol fuelled engine. The engine maycontain an exhaust treatment device.

The composition of the present invention comprising a sulphur freereaction product of (a)(i) and (a)(ii) may or may not include metalcontaining detergents and can be present in sufficient amount to providedetergent performance to an internal combustion engine where thedetergent performance can include neutralizing acids, preventingcorrosion, removing deposits, suspending deposits and depositprecursors, preventing wear, preventing oxidation, improving exhaustemissions (since the sulphur free reaction product contributes nosulphur or phosphorus and at most only minor amounts of sulphated ash tothe composition), or combinations thereof. In an embodiment of theinvention a method for lubricating an internal combustion enginecomprises supplying to the engine a composition comprising the sulphurfree reaction product of (a)(i) and (a)(ii), and in another embodimentthe supplied composition has a reduced level of sulphur, phosphorus andsulphated ash as described below. In a further embodiment of theinvention a method to provide detergent performance to an internalcombustion engine comprises supplying to the engine a compositioncomprising the sulphur free reaction product of (a)(i) and (a)(ii), inanother embodiment where the composition supplied to the engine has areduced level of sulphur and phosphorus and sulphated ash as describedbelow, and in a still another embodiment where the reaction product of(a)(i) and (a)(ii) contributes no sulphur, no phosphorus, and a minoramount of to no sulphated ash to the composition supplied to the engine.

An embodiment of the invention is a use of the composition of theinvention comprising the sulphur free reaction product of (a)(i) and(a)(ii) for imparting to an internal combustion engine one or moreproperties selected from the group consisting of improved enginecleanliness, decreased oxidation, decreased wear, decreased emissionsand decreased poisoning of exhaust emission catalysts, and in anotherembodiment of the use the composition has reduced levels of sulphur,phosphorus and sulphated ash as described below. A further embodiment ofthis invention is a use of the composition comprising the sulphur freereaction product of (a)(i) and (a)(ii) for imparting to an internalcombustion engine an improvement in one or more performance propertiesselected from the group consisting of cleanliness, wear and exhaustemissions, and in another embodiment of the use the composition hasreduced levels of sulphur, phosphorus and sulphated ash as describedbelow.

Often the composition has a total sulphur content below 0.5 wt %, in oneaspect below 0.3 wt %, in another aspect below 0.1 wt % and in yetanother aspect near 0 wt %. Often the major source of sulphur in thecomposition of the invention is derived from diluent oil. Usually thediluent oil is used in the manufacturing processes used for preparingmany known additives such as detergents or dispersants. Excluding thediluent oil, the composition of the invention often have a sulphurcontent of 700 ppm or less, in one aspect 600 ppm or less, in anotheraspect 300 ppm or less, in yet another aspect 100 ppm or less and in yetanother aspect 50 ppm or less such as less than 30 ppm, 25 ppm or less,20 ppm or less and 15 ppm or less. When sulphur from the diluent oil isincluded, the sulphur content of the composition is often increased byup to 800 ppm, in one aspect up to 600 ppm and in another aspect up to400 ppm, for instance about 200 ppm or about 300 ppm. In one embodimentthe sulphur is present from 1 ppm or 10 ppm to 50 ppm or 200 ppm. In oneembodiment of the invention the composition is free of sulphur excludingsulphur derived from diluent oil.

Often the composition has a total phosphorus content below 0.1 wt %, inone aspect below 0.085 wt %, in another aspect below 0.07 wt %, in yetanother aspect below 0.055 wt % and in yet another aspect below 0.05 wt% of the composition, such as 200 ppm or less, in one aspect 100 ppm orless, in another aspect 50 ppm or less and in yet another aspect 10 ppmor less. In one embodiment the phosphorus is present from 1 ppm or 10ppm to 50 ppm or 200 ppm. In one embodiment of the invention thecomposition is free of phosphorus.

Often the composition has a total sulphated ash content below 1.5 wt %,in one aspect below 1.1 wt %, in another aspect below 1.0 wt %, in yetanother aspect below 0.08 wt % and in yet another aspect below 0.05 wt %of the composition, such as 0.04 wt % or less, 0.03 wt % or less or 0.02wt % or less. In one embodiment of the invention the compositioncontains ash present from 0.01 wt % to 0.03 wt %.

The following examples provide an illustration of the invention. Theseexamples are nonexhaustive and are not intended to limit the scope ofthe invention.

EXAMPLES Preparative Example A Preparation of PIBPhenol-Formaldehyde-Salicylic Acid

A 2 litre reaction flask is charged with 475 g (0.739 mole, 1 eq)polyisobutenyl phenol derived from high vinylidene polyisobutylene witha number average molecular weight of 550 (GLISSOPAL®550 commerciallyavailable from BASF) and 330 g mineral oil (SN150) and heated to 30° C.Via a pressure equalising dropping funnel, 3.4 g of 50% aqueous KOH(0.030 mole, 0.04 eq) is added all at once. The materials are heated to75° C. followed by addition over 0.5 hour via a pressure equalisingdropping funnel, 81.6 g 37% aqueous formaldehyde (formalin) (1.01 moles,1.367 eq) followed by heating at 75° C. for 2 hours until freeformaldehyde measures less than 2% (by titration). To the reaction ischarged 51.6 g salicylic acid (0.374 mole, 0.51 eq) and the reaction isheated to 140° C. as quickly as possible (0.3 hour) while controllingreflux, draining water of reaction via a Dean Stark trap. The reactionis held at 140° C. for 1.5 hours while collecting 58 ml water. Thematerials are vacuum stripped at 140° C./100 mm Hg (equivalent to 13kPa) over 0.5 hour. The clear and golden residue is the product.Yield=857 g, % K=0.093%. Mass spec, GPC and H¹ and C¹³ NMR indicate thatthe product consists of 2 methylene bridged polyisobutenyl phenolmolecules methylene bridged to one salicylic acid. A more detaileddescription of the reaction process is given in Example 5 ofInternational Publication WO03/018728, page 23.

Preparative Example B Preparation of PIBPhenol-Formaldehyde-3,5-Dihydroxybenzoic acid

The process is the same as Preparative Example A except, 415.5 g ofpolyisobutenyl phenol derived from high vinylidene polyisobutylene witha number average molecular weight of 550 (GLISSOPAL®550 commerciallyavailable from BASF) is used, 290 g mineral oil (SN150) and 50.5 g of3,5-dihydroxybenzoic acid is used instead of salicylic acid.

Preparative Example C Preparation of PIBPhenol-Formaldehyde-4-Hydroxybenzoic Acid

The process is the same as Preparative Example B except, 45.2 g of4-hydroxybenzoic acid is used instead of 3,5-dihydroxybenzoic acid.

Preparative Example D Preparation of PIB Phenol-Formaldehyde-AnthranilicAcid

The process is the same as Preparative Example A except, 200 gpolyisobutenyl phenol derived from high vinylidene polyisobutylene witha number average molecular weight of 550 (GLISSOPAL®550 commerciallyavailable from BASF) is used, 306 g mineral oil (SN150) and 14.1 g ofanthranilic acid instead of salicylic acid. Furthermore after theaddition of anthranilic acid is carried out at 70° C. (instead of 75° C.used in preparative example A) followed by the addition of 85 g ofxylene.

Preparative Example E Preparation of Dodecyl Phenol-FormaldehydeSalicylic Acid

The process is the same as Preparative Example A except, 346 gdodecylphenol (propylene tetramer derived, 1.32 moles, 1 equivalent(eq)); 95.6 g salicylic acid (0.69 mole, 0.52 eq); 226.9 g of 36.7% byweight formaldehyde in water (formalin) (1.70 moles, 1.356 eq); 45 g 25%aqueous ammonia (0.65 mole, 0.5 eq), and 500 g toluene (solvent) areused. A more detailed description of the reaction process is given inExample 1 of International Publication WO03/018728, page 22.

Example 1 Phenol-Formaldehyde-Salicylic Acid and Amino guanidineBicarbonate

To a 1 litre flask, equipped with overhead stirrer and paddle, heatingmantle, splash head, Dean-Stark trap and condenser equipped for waterremoval, pressure equalizing dropping funnel, thermocouple and thermalcontrol unit, is added 450 g of Preparative Example A (60% actives,0.186 moles, 1 equivalent) and 70 g of toluene. This is then heated to85° C., at which point a slurry of aminoguanidine bicarbonate (38 g,0.28 moles, 1.5 equivalents) and distilled water (80 g, about 90° C. toaid solubility in the slurry) is added slowly over 15 minutes via apressure equalising funnel. The reaction turns cloudy. Water removal isobserved almost instantaneously after addition of the slurry. Themixture is heated in 5° C. stages to 130° C. The reaction is then heldfor 2 hours at 130° C. under reflux. Solution clears at this point.Whilst warm, the product is filtered under vacuum through a pad offinely divided diatomaceous earth using a Buchner flask. Analysis of theproduct indicates a sulphated ash of 0.34% (corresponds to less than0.01% of metal believed to be potassium residue from potassium hydroxideused in preparative example 1), TBN of 29 mg KOH/g sample, KinematicViscosity @ 100° C.=391 mm²/s (or cSt) and a nitrogen content of 2.9%.

Example 2 Phenol-Formaldehyde-Salicylic Acid and Ammonia

400 g of the product from Preparative Example A is heated to 80° C. in a1 litre flask fitted with a stirrer, a thermocouple and a nitrogen feed.The flask is then charged dropwise over 15 minutes with 95 cm³ of 2molar ammonia dissolved in methanol. The flask is held at temperaturefor 1.5 hours before being vacuum distilled to remove methanol. Theproduct has a TBN of 17.5 mg KOH/g sample and Kinematic Viscosity @ 100°C.=208.9 mm²/s (or cSt).

Example 3 Phenol-Formaldehyde-Salicylic Acid and Imidazole

313 g of the product from Preparative Example A is heated to 80° C. in a1 litre flask fitted with a stirrer, a thermocouple and a nitrogen feed.The flask is then charged with 17.7 g of imidazole added in smallportions before the addition of 80 g of diluent oil. The flask is heatedto 110° C. for 10 minutes, followed by heating to 120° C. for 1.5 hoursand then heating to 140° C. for 3 hours. The product is vacuumedstripped at 140° C./100 mm Hg (equivalent to 13 kPa) for 3 hours. Theproduct has a TBN of 15.1 mg KOH/g sample and a Kinematic Viscosity @100° C.=95 mm²/s (or cSt).

Example 4 Phenol-Formaldehyde-Salicylic Acid and Ethanolamine

300 g of the product from Preparative Example A is heated to 85° C. in a1 litre flask fitted with a stirrer, a thermocouple and a nitrogen feed.The flask is then charged dropwise over 10 minutes with 20.1 g ofethanolamine. The flask is then heated to 145° C. for 5 hours. Theproduct is vacuumed stripped at 140° C./100 mm Hg (equivalent to 13 kPa)until excess amine is removed. The product has a TBN of 26.8 mg KOH/gsample.

Example 5 Phenol-Formaldehyde-Salicylic Acid and Diethanolamine

The process is the same as Example 4 except 500 g of the product ofPreparative Example A and 92.1 g diethanolamine is used instead ofethanolamine. The product has a TBN of 78.5 mg KOH/g sample.

Example 6 Phenol-Formaldehyde-Salicylic Acid and Triethanolamine

The process is the same as Example 4 except 49.3 g triethanolamine isused instead of ethanolamine. The product has a TBN of 51.3 mg KOH/gsample.

Example 7 Alkylsalicylate and Triethanolamine

200 g of dodecyl salicylic acid is heated to 80° C. in a 500 ml flaskfitted with a stirrer, a thermocouple and a nitrogen line. The flask isthen charged with 34.2 g of triethanolamine, added dropwise over aperiod of 15 minutes. 234 g of diluent oil is added before the flask isheld at 80° C. for 4 hours before being vacuumed stripped at 140° C./100mm Hg (equivalent to 13 kPa). The product has a TBN of 28 mg KOH/gsample and Kinematic Viscosity @ 100° C.=22.2 mm²/s (or cSt).

Example 8 Product of Preparative Example B and Triethanolamine

200 g of the product of Preparative Example B is heated to 80° C. in a500 ml flask fitted with a stirrer, a thermocouple and a nitrogen line.The flask is then charged with 41.4 g of triethanolamine added dropwiseover a period of 15 minutes. 60 g of diluent oil is added beforeincreasing the temperature to 90° C. for 10 minutes followed by heatingto 100° C. for 10 minutes. The flask is then heated to 120° C. for 45minutes followed by heating to 140° C. for 4 hours. The flask is thenvacuum stripped for up to 5 hours at 140° C./100 mm Hg (equivalent to 13kPa). The product has a TBN of 38.5 mg KOH/g sample and KinematicViscosity @ 100° C.=61 mm²/s (or cSt).

Example 9 Product of Preparative Example C and Triethanolamine

The process is the same as Example 8, except 25.2 g of the product ofPreparative Example C is used instead of the product of preparativeexample 2. The product has a TBN of 30 mg KOH/g sample, KinematicViscosity @ 100° C.=132 mm²/s (or cSt).

Example 10 Product of Preparative Example D and Triethanolamine

The process is the same as Example 8, except 13.2 g of the product ofPreparative Example D is used instead of the product of PreparativeExample B. The product has a TBN of 19.2 mg KOH/g sample and KinematicViscosity @ 100° C.=54 mm²/s (or cSt).

Example 11 Product of Preparative Example C and Guanidine Bicarbonate

117 g of the product of Preparative Example C is heated to 80° C. in a500 ml flask fitted with a stirrer, a thermocouple and a nitrogen line.The flask is then charged with 6 g of water and 3.8 g of guanidinebicarbonate is added dropwise over a period of 20 minutes. 27 g ofdiluent oil is added before increasing the temperature to 90° C. for 10minutes followed by heating to 90° C. for 10 minutes. The flask is thenheated to 100° C. for 10 minutes followed by heating to 120° C. for 20minutes and finally heated to 130° C. for 90 minutes. The flask is thenvacuum stripped for up to 2 hours at 130° C./100 mm Hg (equivalent to 13kPa). The product has a TBN of 8.3 mg KOH/g sample and KinematicViscosity @ 100° C.=56.9 mm²/s (or cSt).

Example 12 Product of Preparative Example E and Guanidine Bicarbonate

The process is the same as Example 12, except 11 g of guanidinebicarbonate, 100 g of the product of Preparative Example E and 16 g ofwater are used. The product has a TBN of 29.2 mg KOH/g sample andKinematic Viscosity @ 100° C.=154 mm²/s (or cSt).

Example 13 Product of Phenol-Formaldehyde-Salicylic Acid andTriethylamine

The process is the same as Example 8, except 250 g of the product ofPreparative Example A, 10 g of triethylamine and 71 g of diluent oil areused. The product has a TBN of 5.5 mg KOH/g sample and KinematicViscosity @ 100° C.=65.3 mm²/s (or cSt).

Example 14 Phenol-Formaldehyde-Salicylic Acid and Polyamine

500 g of the product from Preparative Example A, 11.9 g of calciumhydroxide are heated to 80° C. in a 1 litre flask fitted with a stirrer,a thermocouple and a nitrogen feed. The flask is then charged with 20.3g of triethylenetetramine. The flask is then charged with an excess of260 g of carbon dioxide added via a sparge tube. The flask is thenheated to 160° C. in 5° C. increments. The product is vacuumed strippedat 160° C./338 mm Hg (equivalent to 45 kPa) for 30 minutes. The producthas a TBN of 81 mg KOH/g and a nitrogen content of 1.2 wt %.

Example 15 Phenol-Formaldehyde-Salicylic Acid and Guanidine Carbonate

The process is the same as example 1 except 404 g of the product ofPreparative Example A is mixed with 103 g of toluene and 127 g ofguanidine carbonate. The product has a TBN of 29 mg KOH/g and a nitrogencontent of 2.3 wt %.

Reference Example 1 Oil of Lubricating Viscosity

An oil of lubricating viscosity is prepared with (a) 42.5 g of Nexbase™3050 oil, (b) 34.4 g of Nexbase™ 3043 oil, (c) on an oil free basis 0.4g of an amine dispersant viscosity modifier, (d) on an oil free basis2.8 g of polyisobutylene succinimide dispersants, (e) 5 g ofantioxidants including a diphenylamine and a hindered phenol, (f) 0.7 gof an olefin copolymer viscosity modifier and (g) a glycerol monooleatefriction modifier. The composition contains 0 wt % of calcium, 0 wt % ofphosphorus, 0 wt % of sulphur and 0 wt % of zinc.

Invention Lubricating Oil Compositions

A number of lubricating oil compositions are prepared using 5 g of theproduct of Examples 1-13 mixed into the oil of lubricating viscosityderived from Reference Example 1. The lubricating oil composition formedcontaining Example 1 is titled “Lubricating Oil Composition Example 1”,Example 2 is titled “Lubricating Oil Composition Example 2”, etc. toExample 13, titled “Lubricating Oil Composition Example 13”. Thecomposition has a KV100 of 13.11 mm²/s (or cSt) and a sulphated ashcontent of 0 wt %.

Lubricating Oil Composition Example 14 is prepared by adding on an oilfree basis 1.96 wt % of the product of Example 14 to a lubricating oilcomposition containing (a) on an oil free basis 6.45 wt % of dispersant,(b) on an oil free basis 1.83 wt % of detergent, (c) 3.15 wt % ofantioxidants including a diphenylamine and a hindered phenol, (d) 0.76wt % of zinc dialkyl dithiophosphate and (e) 85.85 wt % of a API GroupII Jurong™ oil (69 wt % of the oil is Jurong™ 150N base oil and 31 wt %Jurong™ 500N base oil) of lubricating viscosity.

Reference Example 2 Top Tier European Passenger Car Oil Formulation

Reference Example 2 is a successful European top tier passenger car oilformulation containing zinc dithiophosphate. The elemental analysis ofthe oil formulation indicates a calcium content of 3307 ppm, aphosphorus content of 889 ppm, a sulphur content of 2645 ppm and a zinccontent of 959 ppm. The oil formulation has a KV100 of 11.3 mm²/s (orcSt) and sulphated ash content of 1.26 wt %.

Reference Example 3

Reference Example 3 is the same lubricating oil composition asLubricating Oil Composition Example 14 except that it does not containthe product of Example 14.

Test 1: HFRR of Lubricating Oil Composition Examples 1-13 and ReferenceExamples 1-2

Examples 1-13 and Reference Examples 1-2 are evaluated for wearperformance in a programmed temperature high frequency reciprocating rig(HFRR) available from PCS Instruments. HFRR conditions for theevaluations are 200 g load, 75 minute duration, 1000 micrometer stroke,20 hertz frequency, and temperature profile of 15 minutes at 40° C.followed by an increase in temperature to 160° C. at a rate of 2° C. perminute. Wear scar in micrometers and film formation as percent filmthickness were then measured with lower wear scar values and higher filmformation values indicating improved wear performance.

The percent film thickness is based on the measurement of electricalpotential between an upper and a lower metal test plate in the HFRR.When the film thickness is 100%, there is a high electrical potentialfor the full length of the 1000 micrometre stroke, suggesting no metalto metal contact. Conversely for a film thickness of 0% there is noelectrical potential suggesting continual metal to metal contact betweenthe plates. For intermediate film thicknesses, there is an electricalpotential suggesting the upper and lower metal test plate have a degreeof metal to metal contact as well as other areas with no metal to metalcontact. The wear scar and film formation results obtained are presentedin Table 1.

TABLE 1 Wear Scar and Film Formation Data Wear Scar Film Example (μm)Formation Lubricating Oil Composition Example 1 141 74 Lubricating OilComposition Example 2 167 25 Lubricating Oil Composition Example 3 17624 Lubricating Oil Composition Example 4 156 23 Lubricating OilComposition Example 5 173 22 Lubricating Oil Composition Example 6 193 6Lubricating Oil Composition Example 7 219 2 Lubricating Oil CompositionExample 8 207 6 Lubricating Oil Composition Example 9 181 13 LubricatingOil Composition Example 10 175 20 Lubricating Oil Composition Example 11162 40 Lubricating Oil Composition Example 12 176 13 Lubricating OilComposition Example 13 178 27 Reference Example 1 189 12 ReferenceExample 2 126 88

The analysis shows the compositions of the invention have antiwearperformance and Example 1 is comparable with Reference Example 2.

Test 2: HFRR of Lubricating Oil Composition Example 14 and ReferenceExample 3

The apparatus used is the same as Test 1. However Example 14 andReference Example 3 are treated with 1 wt % cumene hydroperoxide. Theexamples are then evaluated using the HFRR conditions a 500 g load, 75minute duration, 1000 micrometer stroke, 20 hertz frequency, andisothermal temperature profile at 105° C. The wear scar and filmformation results obtained are presented in Table 2.

TABLE 2 Wear Scar and Film Formation Data Average Wear Scar (μm) from 3HFRR Film Example Experiments Formation Lubricating Oil CompositionExample 14 223 45 Reference Example 3 246 2

The analysis shows the composition containing Example 14 has on averagea better antiwear result compared with Reference Example 3.

Test 3: Pressure Differential Scanning Calorimetry

A Pressure Differential Scanning calorimetry (PDSC) test is carried outbased on the Coordinating European Council (CEC) test method L-85-T-99.The results are based on the oxidation induction time. Better PDSCresults are obtained for examples with higher oxidation induction times.The results obtained are:

Oxidation induction Example Time (mins) Reference Example 3 82.5Lubricating Oil Composition Example 14 95

The analysis shows that the composition containing Example 14 has animproved oxidation induction time result compared with Reference Example3.

Test 4: Komatsu Hot Tube

The Komatsu Hot Tube Test (KHT) uses glass tubes placed through aluminumheater block and heated to 280° C. with an air flow of 10 cc/min and anoil flow of 0.31 cc/hr. The sample is pumped via a syringe pump throughthe glass tube for 16 hours. At end of test, the tubes are rinsed andweighed. The tube is also rated visually, using a 0-10 scale with 0being a black tube and 10 a clean tube. The results obtained are:

Example Deposit Control Reference Example 3 2.5 Lubricating OilComposition Example 14 9

The analysis shows the composition containing Example 14 has reduceddeposit formation compared with Reference Example 3.

Test 5: Dispersant Dilution Test

The dispersant dilution test is reported as a sludge to chemical ratiowhich represents the lowest concentration of chemical to suspend anartificial sludge in an oil solution as described in U.S. Pat. Nos.4,146,489 and 5,814,586. Higher values for the tube number and ratioindicate that a chemical is more effective in suspending sludge. Theresults obtained are presented in Table 3.

TABLE 3 Sludge Dilution Test Tube Sludge to Chemical Example NumberRatio Reference Example 1 1 6 Lubricating Oil Composition Example 1 6125 Lubricating Oil Composition Example 15 5 23

The results show that the compositions containing Examples 1 and 15 haveimproved dispersant properties compared with Reference Example 1.

Overall the composition of the invention improves engine cleanliness,decreases oxidation, decreases wear, decreases emissions and decreasespoisoning of exhaust emission catalysts.

Each of the documents referred to above is incorporated herein byreference. Except in the Examples, or where otherwise explicitlyindicated, all numerical quantities in this description specifyingamounts of materials, reaction conditions, molecular weights, number ofcarbon atoms, and the like, are to be understood as modified by the word“about.” Unless otherwise indicated, each chemical or compositionreferred to herein should be interpreted as being a commercial gradematerial which may contain the isomers, by-products, derivatives, andother such materials which are normally understood to be present in thecommercial grade. However, the amount of each chemical component ispresented exclusive of any solvent or diluent oil, which may becustomarily present in the commercial material, unless otherwiseindicated. It is to be understood that the upper and lower amount,range, and ratio limits set forth herein may be independently combined.Similarly, the ranges and amounts for each element of the invention maybe used together with ranges or amounts for any of the other elements.As used herein, the expression “consisting essentially of” permits theinclusion of substances that do not materially affect the basic andnovel characteristics of the composition under consideration.

What is claimed is:
 1. A composition comprising: (a) a sulphur freereaction product of: (i) a hydrocarbyl substituted aromatic compoundcontaining an acidic group selected from the group consisting of acarboxylic group, a hydroxyl group and mixtures thereof; and (ii) anorganic nitrogen-containing base reacted with the acidic group; and (b)an oil of lubricating viscosity.
 2. The composition of claim 1 furthercomprising at least one other performance additive selected from thegroup consisting of dispersants, antioxidants, foam inhibitors,demulsifiers, friction modifiers, and viscosity modifiers.
 3. Thecomposition of claim 1, wherein component (a) is present at about 0.01wt % to about 40 wt %; the oil of lubricating viscosity is present at upto about 99.99 wt %; and wherein other performance additives are presentat 0 wt % to about 30 wt % of the composition.
 4. The composition ofclaim 1, wherein the total sulphur content of the composition is belowabout 0.5 weight percent; wherein the total phosphorus content of thecomposition is below about 0.07 weight percent; and wherein the totalsulphated ash content of the composition is below about 1.5 weightpercent.
 5. The composition of claim 4, wherein the total sulphurcontent is below about 0.1 weight percent; wherein the total phosphoruscontent is about 100 ppm or less; and wherein the total sulphated ashcontent is below about 0.08 weight percent.
 6. The composition of claim1, wherein (a)(i) is at least one member selected from the groupconsisting of (1) an oligomeric reaction product of anhydrocarbyl-substituted phenol, an aldehyde, and a carboxyl-substitutedphenol; (2) an oligomeric reaction product of a hydrocarbyl-substitutedphenol, an aldehyde, and a carboxyl-substituted phenylamine; (3) ahydrocarbyl-substituted, carboxyl-substituted phenol; (4) ahydrocarbyl-substituted, carboxyl-substituted phenylamine; and (5) anoligomeric reaction product of an hydrocarbyl-substituted phenol and analdehyde.
 7. The composition of claim 6, wherein (a)(i)(1) or (a)(i)(2)is a substantially linear compound comprising at least one unit of theformula (I)

or the formula (II)

wherein each end of the compound is terminated by a unit of the formula(III) or the formula (IV)

and wherein the units of the compound are linked by divalent bridginggroups which may be the same or different for each linkage; U is ahydroxyl group for (a)(i)(1) or is selected from the group consisting of—NH₂, —NHR¹, —N(R¹)₂ and mixtures thereof for (a)(i)(2) wherein R¹ is ahydrocarbyl group containing 1 to 5 carbon atoms; R² is a hydroxyl or ahydrocarbyl group and j is 0, 1 or 2; R³ is hydrogen or a hydrocarbylgroup; f is 1, 2 or 3; R⁴ is a hydrocarbyl group or a substitutedhydrocarbyl group and g is 1, 2 or 3 provided that at least one R⁴ groupcontains 8 or more carbon atoms; and wherein the compound on averagecontains at least one unit of formula (I) or (III) and at least one unitof formula (II) or (IV) and the ratio of the total number of units (I)and (III) to the total number of units of (II) and (IV) in the compoundis about 0.1:1 to about 2:1.
 8. The composition of claim 6, wherein(a)(i) is an alkyl-substituted salicylic acid.
 9. The composition ofclaim 1, wherein (a)(ii) is at least one member selected from the groupconsisting of (1) an amino-containing imine or a reactive equivalentthereof; (2) ammonia or a reactive equivalent thereof; (3) a monoamine;(4) a polyamine; (5) a nitrogen containing heterocycle; (6) anaminoalcohol; (7) a tetraalkylammonium salt; and (8) a non-heterocyclicaromatic amine.
 10. The composition of claim 9, wherein (a)(ii)(1) is atleast one member selected from the group consisting of guanidine,aminoguanidine, 1,3-diaminoguanidine, acetamidine, formamidine,benzamidine, 3- and 4-aminobenzamidine, and reactive equivalentsthereof.
 11. The composition of claim 9, wherein (a)(ii)(3) is ahydrocarbyl substituted primary, secondary or tertiary monoamine ormixture thereof.
 12. The composition of claim 9, wherein (a)(ii)(4) isan alkylenediamine, a polyethylenepolyamine, or a mixture thereof. 13.The composition of claim 9, wherein (a)(ii)(5) is a pyrrole, apyrrolidine, an imidazole, an imidazoline, a piperazine, a pyrazole, anoxazole, a pyridine, a piperidine, a pyrimidine, a purine, abenzotriazole, a 1,2,4-triazole, a quinoline, an isoquinoline, acarbazole or mixtures thereof.
 14. The composition of claim 9, wherein(a)(ii)(6) is an aminoalcohol containing 1 to 6 hydroxyl groups, 1 to 8amino groups, and 2 to 50 carbon atoms.
 15. The composition of claim 14,wherein the aminoalcohol is a monoalkanolamine, a dialkanolamine, atrialkanolamine or mixtures thereof.
 16. The composition of claim 1,wherein component (a) is free of metal.
 17. A process for thepreparation of the composition of claim 1, comprising: (a) heatingreactants (a)(i) and (a)(ii); (b) optionally holding the product of step(a) under vacuum; and (c) adding the product of step (a) or (b) to anoil of lubricating viscosity.
 18. A product prepared by the process ofclaim
 17. 19. A method for lubricating an internal combustion engine,comprising supplying to the engine the composition claim
 1. 20. The useof the composition of claim 1 for imparting to an internal combustionengine an improvement in one or more performance properties selectedfrom the group consisting of cleanliness, wear and exhaust emissions.21. A composition comprising: (a) a sulphur free reaction product of:(i) a hydrocarbyl substituted aromatic compound containing a carboxyland/or hydroxyl acidic group and selected from the group consisting of(1) an oligomeric reaction product of a hydrocarbyl-substituted phenol,an aldehyde, and a carboxyl-substituted phenol; (2) an oligomericreaction product of a hydrocarbyl-substituted phenol, an aldehyde, and acarboxyl-substituted phenylamine; and mixtures thereof; and (ii) anorganic nitrogen-containing base reacted with the acidic group of(a)(i).
 22. The composition of claim 1 wherein the reaction product ofcomponent (a) is a reaction product of components (a)(i), (a)(ii) and(a)(iii) a metal-containing base.